Recently i have been getting messages that pops up randomly while i use the computer it saids your computer is has been infected with malware and it tells my me to run this anti virus that it offers. I looked really suspicious to me and looked like a rogue anti virus program so i exit it. Later this day while noton was doing its scanning it said a downloader virus was detected and blocked but my internet connection seems to be slower lately.Are there any ways of making sure if my computer is infected or not?Please help